1. Field of the Invention
The present invention relates generally to dental implants and, in particular, to a dental implant carrier with resilient fingers for reliably and releasably holding a dental implant and for interfacing with a packaging vial.
2. Background of the Related Art
Dental implants are surgically implanted in a patient's jawbone to provide anchors for prosthetic devices such as artificial teeth, crowns, bridges, dentures and the like. Dental implants allow people who lose their teeth to be able to smile, speak, and chew well and comfortably.
Typically, the dental implant that is implanted in the bone of a patient's jawbone supports a socket. This socket is accessible through the overlying gum tissue for receiving and supporting one or more dental attachments or components, such as healing screws, impression copings and abutments, among others. In turn, some of these components are useful to fabricate and/or to support the prosthodontic restoration.
Dental implant assemblies are generally packaged in a sterile environment and include the implant, an implant carrier and a healing screw. The carrier is used to hold the implant within a vial and during transport to a surgical site, and can also serve as a cap for the vial. Since the dental implant package is usually sterilized, the carrier allows the dental implant to be transported with minimal risk of contamination due to contact with the operator. The carrier also permits the implant to be inserted in a hole, osteotomy or alveolar cavity in the jawbone of a patient. In many cases, the dental implant assembly of the implant, carrier and healing screw is commercialized with the healing screw threadably engaged with the implant socket and the carrier engaged with the healing screw.
Such a commercialized dental implant assembly is typically used in conjunction with non-threaded or "cylindrical implants." Cylindrical implants comprise a non-threaded and generally smooth body portion which is simply press-fitted into the osteotomy. The other popular type of implant is usually referred to as a "threaded implant" and comprises a threaded body portion which is screwed into the osteotomy. The choice of implant is usually dictated by the particular bone structure surrounding the osteotomy and in many instances on the particular personal preference of the dentist or periodontist. A typical commercialized dental implant assembly with a threaded implant may include one or more additional components such as an insertion tool/post and an insertion tool screw for facilitating in the transfer and seating of the threaded implant and healing screw.
In use, the first step usually involves making an incision in the patient's gum. Next, typically, a hole or osteotomy is drilled in the jawbone of the patient and the implant is fixtured into the osteotomy. The carrier is used to transport the implant to the surgical site and to seat the implant in its proper subgingival position. For cylindrical implants, the carrier is removed from the assembly leaving the healing screw threadably coupled to the cylindrical implant in the osteotomy. For threaded implants, the carrier is then pulled from the insertion tool screw. The insertion tool screw is removed from the threaded implant and the healing screw is threaded into the socket of the threaded implant. The healing screw prevents the ingrowth of bone inside the implant.
This is followed by a healing period in which the bone is allowed to grow and surround and retain the implant (or to osseointegrate with the implant) and the gum tissue is allowed to heal over the implant and the healing screw. For implants in the mandible, healing typically requires about three months; for implants in the maxilla, the healing period is usually about six months. The healing screw protects the implant socket against bone/tissue ingrowth during this healing period, and also prevents the entry of bacteria or other contaminants into the exposed central socket/bore of the implant.
After the osseointegration occurs and the gun has healed, the gum is reopened by making an incision in it and the healing screw is removed. A suitable healing abutment is attached to the implant. A second healing period ensues in which the gum tissue is allowed to heal around the healing abutment Typically, this second healing period lasts from four to eight weeks.
After the second healing period, the healing abutment is removed from the implant. Typically, an impression is taken of the patient's mouth to fabricate a prosthesis or dental restoration. An abutment which supports the final restoration is attached to the implant. Lastly, the restoration is cemented or screwed to the abutment and/or implant to complete the placement of the prosthodontic restoration in the patient's mouth.
Referring in particular to cylindrical dental implant assemblies, there are several potential problems associated with conventional cylindrical implant carriers. Conventional carriers generally include a cap at one end for manual gripping and a protrusion or nipple at the other end. The protrusion engages a cavity in the head of the healing screw and provides an interference fit between the carrier protrusion and the healing screw cavity. Since the healing screw is threaded into the implant socket, the implant is thereby held via the carrier and healing screw engagement. The carrier is bent relative to the head of the screw and/or pulled, to remove it from the healing screw. Such a cylindrical implant carrier is described in U.S. Pat. No. 5,030,096, incorporated herein by reference.
The holding mechanism as incorporated by the above-mentioned interference fit has demonstrated a low frequency of failure. It is not uncommon for commercialized dental implant assemblies to be transported by common carrier and be exposed to temperature variations and vibrations. This can result in disengagement of the carrier and the implant during shipping. Moreover, a dental implant assembly may be subject to similar adverse temperature variations and vibrations while it is on-the-shelf or in storage. In many cases, this on-the-shelf and storage period may span over a period of several years. Hence, the quality of the interference fit between the cylindrical implant carrier and the healing screw may degrade over time. It is especially inconvenient if the dental implant slips out of the carrier during a dental procedure. Also, the interference friction fit between the carrier protrusion and the healing screw cavity provides poor manufacturing repeatability and, therefore, can undesirably result in either insufficient or considerably large holding forces between the cylindrical implant carrier and the healing screw.
Additionally, the removal mechanism of the carrier from the healing screw can result in breakage of the carrier protrusion, since this removal involves bending of the carrier relative to the head of the healing screw. The torque generated during such bending may be sufficiently high to cause breakage or fracture of the protrusion from the carrier, especially since the protrusion is forming a frictional interference fit with the healing screw cavity. Again, this is inconvenient during a dental procedure.
One popular technique of packaging the commercialized dental implant assembly utilizes an extrusion or annular ring. The extrusion is fabricated from a resilient material and slides onto a medial portion of the carrier adjacent to the cap of the carrier. Thus when the dental implant is packaged in the vial the extrusion serves to provide an interference fit with the wall of the vial while the carrier cap serves as a cap for the package.
Disadvantageously, this frictional interference fit between the extrusion and the vial has demonstrated a low frequency of failure for reasons similar to those discussed above. These being exposure to shock and temperature variations during shipping and handling, and even possibly during on-the-shelf and storage periods. Additionally, the interference friction fit provides poor manufacturing repeatability and, therefore, can result in either insufficient or considerably large retaining forces between the carrier and the vial.
Moreover, and undesirably, the fabrication of the extrusion requires the manufacture of an additional component for the dental implant packaging and increases the number of components comprising the dental implant packaging. Also, the assembly of the packaging requires the additional step of sliding the extrusion over the carrier. All this disadvantageously adds to the cost of the dental implant packaging.
Therefore, it would be desirable to provide a dental implant packaging that can reliably and effectively hold a dental implant over a substantially prolonged period of time while being generally unaffected by ambient inclement conditions. There is also a need to provide a dental implant packaging for reliably and releasably fixturing a dental implant assembly in a packaging vial while concurrently maintaining simplicity in design and low cost.